Here's one more vote for the notion that significant changes are so rare you can count them on your thumbs. I think the last one was the introduction of indexed shifting, and I'm not fully convinced even that was a big step forward. A couple of my bikes are still friction-shift, and I switch back and forth without even thinking about it.
I'll grant that I'm sort of a retro-grouch, but for the kind of riding I do, meaningful progress stopped at seven-speed cassettes. I do like seven more than five, but nine aren't any better than seven, which leads me to question why I need 10.